Charging system for electric vehicle and method for controlling charging of electric vehicle

ABSTRACT

A charging system for an electric vehicle and a method for controlling charging of an electric vehicle are provided. The charging system comprises: a power battery (10); a charge-discharge socket (20); an external power supply device (1002); a charging connection device (1001); and an energy control device (1003), comprising: a three-level bidirectional DC-AC module (30); a charge-discharge control module (50); and a control module (60) configured to control the charge-discharge control module (50) according to a current working mode of the electric vehicle. The energy control device (1003) and the external power supply device (1002) communicate by transmitting a modulated PWM signal to each other via the charging connection device (1001), and the control module (60) controls the three-level bidirectional DC-AC module (30) and the charge-discharge control module (50) to charge the power battery (10) by the external power supply device (1002).

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national phase entry under 35 U.S.C. § 371 ofInternational Application No. PCT/CN2014/081317, filed on Jun. 30, 2014,which claims priority and benefits of Chinese Patent Application No.201310733561.8 filed with State Intellectual Property Office on Dec. 26,2013, and Chinese Patent Application No. 201310269952.9 filed with StateIntellectual Property Office on Jun. 28, 2013, the entire contents ofall of which are incorporated herein by reference.

FIELD

Embodiments of the present disclosure generally relate to an electricvehicle field, and more particularly to a charging system for anelectric vehicle and a method for controlling charging of an electricvehicle.

BACKGROUND

At present, an electric vehicle is charged by visiting a chargingstation. However, because the number of the charging stations islimited, it is inconvenient to charge the electric vehicle, thusaffecting a popularity of the electric vehicle.

Currently, the electric vehicle is charged either by an AC electricityof low power (such as, 3.3 KW, 7 KW, 30 KW) or a DC electricity of highpower. However, the charging at a DC charging station has disadvantagesof low efficiency, long charging time, high cost and large coveringarea, and thus it is very difficult to popularize the charging station.In addition, due to the limited space of the electric vehicle, thein-vehicle charger restricted by the volume thereof is unable to meetthe requirement of high charging power.

Besides, a charging apparatus including a DC-DC module is currently usedto charge the electric vehicle, which cannot meet the need of quickcharging of the electric vehicle.

SUMMARY

Embodiments of the present disclosure seek to solve at least one of theproblems existing in the related art to at least some extent.

According to embodiments of a first broad aspect of the presentdisclosure, a charging system for an electric vehicle is provided. Thecharging system includes: a power battery; a charge-discharge socket; anexternal power supply device; a charging connection device comprising afirst plug configured to connect with the external power supply deviceand a second plug configured to connect with the charge-dischargesocket; and an energy control device, comprising: a three-levelbidirectional DC-AC module having a first DC terminal connected with afirst terminal of the power battery and a second DC terminal connectedwith a second terminal of the power battery; a charge-discharge controlmodule having a first terminal connected with an AC terminal of thethree-level bidirectional DC-AC module and a second terminal connectedwith the charge-discharge socket; and a control module connected with athird terminal of the charge-discharge control module and a controlterminal of the three-level bidirectional DC-AC module and configured tocontrol the charge-discharge control module according to a currentworking mode of the electric vehicle; wherein the energy control deviceand the external power supply device communicate by transmitting amodulated PWM signal to each other via the charging connection device,and the control module is configured to control the three-levelbidirectional DC-AC module and the charge-discharge control module tocharge the power battery by the external power supply device.

With the charging system according to embodiments of the presentdisclosure, by employing the three-level bidirectional DC-AC module inthe energy control device, a common-mode voltage is reduced, a leakagecurrent is decreased and a harmonic wave is weakened. Furthermore, aDC-DC voltage increasing and decreasing module is not necessarilyrequired in the energy control device, thus realizing a high powercharging, reducing a bus voltage, improving a charging efficiency andshortening a charging time. In addition, a charging pile is notnecessarily required, thus reducing a charging cost, which is beneficialto a popularization and promotion of the electric vehicle.

According to embodiments of a second broad aspect of the presentdisclosure, a method for controlling charging of an electric vehicle isprovided. The method includes: detecting a modulated PWM signaltransmitted between an energy control device and an external powersupply device via a charging connection device; establishing acommunication between the energy control device and the external powersupply device according to the modulated PWM signal; and controlling athree-level bidirectional DC-AC module and a charge-discharge controlmodule of the energy control device to charge the power battery by theexternal power supply device.

With the method for controlling charging of an electric vehicleaccording to embodiments of the present disclosure, by controlling thethree-level bidirectional DC-AC module, the power battery is charged bythe external power supply device, such that the electric vehicle may becharged by a single-phase or a three-phase high power electricity, acharging efficiency of the electric vehicle is increased, a chargingtime is shortened, it is convenient for user to fast charge the electricvehicle anytime and anywhere. In addition, a charging pile is notnecessarily required, thus reducing a charging cost, which is beneficialto a popularization and promotion of the electric vehicle.

Additional aspects and advantages of embodiments of present disclosurewill be given in part in the following descriptions, become apparent inpart from the following descriptions, or be learned from the practice ofthe embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of embodiments of the presentdisclosure will become apparent and more readily appreciated from thefollowing descriptions made with reference to the accompanying drawings,in which:

FIG. 1 is a schematic diagram of a power system for an electric vehicleaccording to an embodiment of the present disclosure;

FIG. 2 is a circuit diagram of a power system for an electric vehicleaccording to an embodiment of the present disclosure;

FIG. 3A is a circuit diagram of a charging system for an electricvehicle according to an embodiment of the present disclosure;

FIG. 3B is a flow chart of a method for controlling charging of anelectric vehicle according to an embodiment of the present disclosure;

FIG. 3C is a flow chart of a method for controlling charging of anelectric vehicle according to an embodiment of the present disclosure;

FIG. 3D is a schematic diagram of a power system for an electric vehicleaccording to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of a control module according to anembodiment of the present disclosure;

FIG. 5 is a flow chart of determining a function of a power system foran electric vehicle according to an embodiment of the presentdisclosure;

FIG. 6 is a schematic diagram showing a power system for an electricvehicle according to an embodiment of the present disclosure executing amotor driving control function;

FIG. 7 is a flow chart of determining whether to start acharge-discharge function for a power system for an electric vehicleaccording to an embodiment of the present disclosure;

FIG. 8 is a flow chart of controlling a power system for an electricvehicle in a charging mode according to an embodiment of the presentdisclosure;

FIG. 9 is a flow chart of controlling a power system for an electricvehicle according to an embodiment of the present disclosure, whenending charging the electric vehicle;

FIG. 10 is a circuit diagram of a connection between an electric vehicleaccording to an embodiment of the present disclosure and a power supplyapparatus;

FIG. 11 is a flow chart of a method for controlling charging an electricvehicle according to an embodiment of the present disclosure;

FIG. 12 is a schematic diagram of a charge-discharge socket according toan embodiment of the present disclosure;

FIG. 13 is a schematic diagram of an off-grid on-load discharge plugaccording to an embodiment of the present disclosure;

FIG. 14 is a block diagram of a power carrier communication system foran electric vehicle according to an embodiment of the presentdisclosure;

FIG. 15 is a block diagram of a power carrier communication device;

FIG. 16 is a schematic diagram of communications between eight powercarrier communication devices and corresponding control devices;

FIG. 17 is a flow chart of a method for receiving data by a powercarrier communication system; and

FIG. 18 is a schematic diagram showing a connection between a motorcontroller for an electric vehicle and other parts of the electricvehicle according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will be made in detail to embodiments of the presentdisclosure. Embodiments of the present disclosure will be shown indrawings, in which the same or similar elements and the elements havingsame or similar functions are denoted by like reference numeralsthroughout the descriptions. The embodiments described herein accordingto drawings are explanatory and illustrative, not construed to limit thepresent disclosure.

The following description provides a plurality of embodiments orexamples configured to achieve different structures of the presentdisclosure. In order to simplify the publishment of the presentdisclosure, components and dispositions of the particular embodiment aredescribed in the following, which are only explanatory and not construedto limit the present disclosure. In addition, the present disclosure mayrepeat the reference number and/or letter in different embodiments forthe purpose of simplicity and clarity, and the repeat does not indicatethe relationship of the plurality of embodiments and/or dispositions.Moreover, in description of the embodiments, the structure of the secondcharacteristic “above” the first characteristic may include anembodiment formed by the first and second characteristic contacteddirectly, and also may include another embodiment formed between thefirst and the second characteristic, in which the first characteristicand the second characteristic may not contact directly.

In the description of the present disclosure, unless specified orlimited otherwise, it should be noted that, terms “mounted,” “connected”and “coupled” may be understood broadly, such as electronic connectionor mechanical connection, inner communication between two elements,direct connection or indirect connection via intermediary. These havingordinary skills in the art should understand the specific meanings inthe present disclosure according to specific situations.

With reference to the following descriptions and drawings, these andother aspects of embodiments of the present disclosure will be distinct.In the descriptions and drawings, some particular embodiments aredescribed in order to show means of the principles of embodimentsaccording to the present disclosure, however, it should be appreciatedthat the scope of embodiments according to the present disclosure is notlimited. On the contrary, embodiments of the present disclosure includeall the changes, alternatives, and modifications falling into the scopeof the spirit and principles of the attached claims.

A charging system for an electric vehicle according to embodiments ofthe present disclosure can be implemented based on a power system for anelectric vehicle described in the following.

The power system and the electric vehicle having the same according toembodiments of the present disclosure are described in the followingwith reference to the drawings.

As shown in FIG. 1, the power system for the electric vehicle accordingto an embodiment of the present disclosure includes a power battery 10,a charge-discharge socket 20, a motor M, a three-level bidirectionalDC-AC module 30, a motor control switch 40, a charge-discharge controlmodule 50 and a control module 60.

The three-level bidirectional DC-AC module 30 has a first DC terminal a1connected with a first terminal of the power battery 10 and a second DCterminal a2 connected with a second terminal of the power battery 10.The three-level bidirectional DC-AC module 30 is configured to implementa DC-AC conversion. The motor control switch 40 has a first terminalconnected with an AC terminal a3 of the three-level bidirectional DC-ACmodule 30 and a second terminal connected with the motor M for theelectric vehicle. The charge-discharge control module 50 has a firstterminal connected with the AC terminal a3 of the three-levelbidirectional DC-AC module 30 and a second terminal connected with thecharge-discharge socket 20. The control module 60 is connected with themotor control switch 40 and the charge-discharge control module 50respectively and is configured to control the motor control switch 40and the charge-discharge control module 50 according to a currentworking mode of a power system, such that the electric vehicle canswitch between a driving mode and a charge-discharge mode.

Moreover, in some embodiments of the present disclosure, the currentworking mode of the power system may include the driving mode and thecharge-discharge mode. In other words, the working mode of theelectrical vehicle may include the driving mode and the charge-dischargemode. It should be noted that the charge-discharge mode means that theelectric vehicle is either in a charging mode or in a discharging mode.

When the power system is in the driving mode, the control module 60controls the motor control switch 40 to turn on to drive the motor Mnormally, and controls the charge-discharge control module 50 to turnoff. It should be noted that the motor control switch 40 may alsoinclude two switches K3 and K4 connected with a two-phase input to themotor, or even one switch, provided that the control on the motor may berealized. Therefore, other embodiments will not be described in detailherein.

When the power system is in the charge-discharge mode, the controlmodule 60 controls the motor control switch 40 to turn off to stop themotor M and controls the charge-discharge control module 50 to turn onso as to start the three-level bidirectional DC-AC module 30, such thatan external power source can charge the power battery 10 normally. Thefirst DC terminal a1 and the second DC terminal a2 of the three-levelbidirectional DC-AC module 30 are connected with a positive terminal anda negative terminal of a DC bus of the power battery 10 respectively.

In an embodiment of the present disclosure, as shown in FIG. 2, thethree-level bidirectional DC-AC module 30 includes a first capacitor C1,a second capacitor C2, and a first IGBT1 to a twelfth IGBT12.

Specifically, the first capacitor C1 and the second capacitor C2 areconnected in series, the first capacitor C1 has a first terminalconnected with the first terminal of the power battery 10 and a secondterminal connected with a first terminal of the second capacitor C2, andthe second capacitor C2 has a second terminal connected with the secondterminal of the power battery 10, in which a first node J1 is definedbetween the first capacitor C1 and the second capacitor C2, in otherwords, the first capacitor C1 and the second capacitor C2 are connectedbetween the first DC terminal a1 and the second DC terminal a2 of thethree-level bidirectional DC-AC module 30. The first IGBT1 and a secondIGBT2 are connected in series and are connected between the first DCterminal a1 and the second DC terminal a2 of the three-levelbidirectional DC-AC module 30, in which a second node J2 is definedbetween the first IGBT1 and the second IGBT2. A third IGBT3 and a fourthIGBT4 are connected in series and are connected between the first nodeJ1 and the second node J2. A fifth IGBT5 and a sixth IGBT6 are connectedin series and are connected between the first DC terminal a1 and thesecond DC terminal a2 of the three-level bidirectional DC-AC module 30,in which a third node J3 is defined between the fifth IGBT5 and thesixth IGBT6. A seventh IGBT7 and an eighth IGBT8 are connected in seriesand are connected between the first node J1 and the third node J3. Aninth IGBT9 and a tenth IGBT10 are connected in series and are connectedbetween the first DC terminal a1 and the second DC terminal a2 of thethree-level bidirectional DC-AC module 30, in which a fourth node J4 isdefined between the ninth IGBT9 and the tenth IGBT10. An eleventh IGBT11and a twelfth IGBT12 are connected in series and are connected betweenthe first node J1 and the fourth node J4. The second node J2, the thirdnode J3 and the fourth node J4 are configured as the AC terminal a3 ofthe three-level bidirectional DC-AC module.

As shown in FIG. 2, the power system for the electric vehicle furtherincludes a first common-mode capacitor C11 and a second common-modecapacitor C12. The first common-mode capacitor C11 and the secondcommon-mode capacitor C12 are connected in series and connected betweenthe first terminal and the second terminal of the power battery 10, inwhich a node between the first common-mode capacitor C11 and the secondcommon-mode capacitor C12 is grounded.

Generally, a leakage current is large in an inverter and grid systemwithout transformer isolation. Compared with a conventional two-levelsystem, the power system according to embodiments of the presentdisclosure adopts the three-level bidirectional DC-AC module 30. Byusing a three-level control and connecting the first common-modecapacitor C11 and the second common-mode capacitor C12 between the firstterminal and the second terminal of the power battery 10, a common-modevoltage can be reduced by half in theory and the large leakage currentproblem generally existing in controllers can also be solved. A leakagecurrent at an AC side can also be reduced, thus satisfying electricalsystem requirements of different countries.

In an embodiment of the present disclosure, as shown in FIG. 2, thepower system for the electric vehicle further includes a filteringmodule 70, a filtering control module 80 and an EMI-filter module 90.

The filtering module 70 is connected between the three-levelbidirectional DC-AC module 30 and the charge-discharge control module50, and is configured to eliminate a harmonic wave. As shown in FIG. 2,the filtering module 70 includes inductors LA, LB, LC connected inparallel and capacitors C4, C5, C6 connected in parallel, in which theinductor LA is connected with the capacitor C6 in series, the inductorLB is connected with the capacitor C5 in series and the inductor LC isconnected with the capacitor C4 in series.

A shown in FIG. 2, the filtering control module 80 is connected betweenthe first node J1 and the filtering module 70, and the control module 60controls the filtering control module 80 to turn off when the powersystem is in the driving mode. The filtering control module 80 may be acapacitor switching relay and may include a contactor K10. TheEMI-filter module 90 is connected between the charge-discharge socket 20and the charge-discharge control module 50 and is mainly configured tofilter interference of conduction and radiation.

It should be noted that a position of the contactor K10 in FIG. 2 ismerely exemplary. In other embodiments of the present disclosure, thecontactor K10 may be disposed at other positions, provided that thefiltering module 70 can be turned off by using the contactor K10. Forexample, in another embodiment of the present disclosure, the contactorK10 can be connected between the three-level bidirectional DC-AC module30 and the filtering module 70.

In an embodiment of the present disclosure, as shown in FIG. 2, thecharge-discharge control module 50 further includes a three-phase switchK8 and/or a single-phase switch K7 configured to implement a three-phaseor a single-phase charge-discharge.

In some embodiments of the present disclosure, when the power system isin the driving mode, the control module 60 controls the motor controlswitch 40 to turn on so as to drive the motor M normally, and controlsthe charge-discharge control module 50 to turn off. In this way, adirect current from the power battery 10 is inverted into an alternatingcurrent via the three-level bidirectional DC-AC module 30 and thealternating current is transmitted to the motor M. The motor M can becontrolled by a revolving transformer decoder technology and a spacevector pulse width modulation (SVPWM) control algorithm.

When the power system is in the charge-discharge mode, the controlmodule 60 controls the motor control switch 40 to turn off so as to stopthe motor M, and controls the charge-discharge control module 50 to turnon, such that the external power source such as a three-phase current ora single-phase current can charge the power battery 10 normally via thecharge-discharge socket 20. In other words, by detecting a chargeconnection signal, an AC grid power system and a vehicle batterymanagement information, a controllable rectification function may beimplemented via the bidirectional DC-AC module 30, and the power battery10 may be charged by the single-phase power source and/or thethree-phase power source.

With the power system for the electric vehicle according to embodimentsof the present disclosure by adopting the three-level bidirectionalDC-AC module, the common-mode voltage and the leakage current arereduced. In addition, by employing the three-level bidirectional DC-ACmodule 30 in the energy device, a common-mode voltage is reduced, aleakage current is decreased and a harmonic wave is weakened.Furthermore, a DC-DC voltage increasing and decreasing module is notnecessarily required in the energy control device, thus realizing a highpower charging, reducing a bus voltage, improving a driving efficiencyand shortening a charging time. For example, the driving efficiency maybe up to 97%, and the charging time may be shortened to about 10minutes. Besides, with the power system according to embodiments of thepresent disclosure, the electric vehicle may be charged without adedicated charging pile, thus reducing cost and facilitatingpopularization of the electric vehicle. Furthermore, the electricvehicle may be directly charged with an AC electricity, whichsignificantly facilitate the use and popularization of the electricvehicle.

The charging system according to embodiments of the present disclosurewill be described in the following.

As shown in FIG. 3A, in an embodiment, the charging system for theelectric vehicle includes: a power battery 10, a charge-discharge socket20, a charging connection device 1001, an external power supply device1002 (i.e. a power supply apparatus 301 shown in FIG. 10) and an energycontrol device 1003.

Specifically, the charging connection device 1001 includes a first plug302 configured to connect with the external power supply device 1002 anda second plug 303 configured to connect with the charge-discharge socket20.

Furthermore, the energy control device 1003 includes: a three-levelbidirectional DC-AC module 30, a charge-discharge control module 50 anda control module 60. The three-level bidirectional DC-AC module 30 has afirst DC terminal a1 connected with a first terminal of the powerbattery 10 and a second DC terminal a2 connected with a second terminalof the power battery 10, and is configured to implement a DC-ACbidirectional conversion. The charge-discharge control module 50 has afirst terminal connected with an AC terminal a3 of the three-levelbidirectional DC-AC module 30 and a second terminal connected with thecharge-discharge socket 20. The control module 60 is connected with athird terminal of the charge-discharge control module 20 and a controlterminal of the three-level bidirectional DC-AC module 30 and isconfigured to control the charge-discharge control module 50 accordingto a current working mode of the electric vehicle.

The energy control device 1003 and the external power supply device 1002communicate by transmitting a modulated PWM signal to each other via thecharging connection device 1001. After a communication between theenergy control device 1003 and the external power supply device 1002 isestablished, the control module 60 controls the three-levelbidirectional DC-AC module 30 and charge-discharge control module 50 tocharge the power battery 10 by the external power supply device 1002.

In an embodiment, the charging system for the electric vehicle includesa battery manager. The battery manager is communicated with the controlmodule 60 via CAN. When the control module is failure free via aself-test, the battery manager controls the power battery to enter acharging state and provide a charging pathway.

The control module 60 is configured to detect a current carryingcapacity of the charging connection device 1001 and/or a load capacityof the external power supply device 1002, such that the control module60 controls the three-level bidirectional DC-AC module 30 according tothe current carrying capacity of the charging connection device 1001and/or the load capacity of the external power supply device 1002, thusadjusting a charging current.

Specifically, as shown in FIG. 10, the charging connection device 1001includes: a plurality of high-voltage terminals, a first detectionterminal (i.e. detecting point 2), a second detection terminal (i.e.detecting point 4) and a communication terminal (i.e. CP terminal), theexternal power supply device 1002 and the energy control device 1003determine a connection state of the first plug 302 and the second plug303 according to the first detection terminal and the second detectionterminal, and the external power supply device 1002 and the energycontrol device 1003 communicate with each other via the communicationterminal. Furthermore, the energy control device 1003 (i.e. a vehiclecontrol device shown in FIG. 10) detects the current carrying capacityof the charging connection device 1001 via the second detection terminal(i.e. detecting point 4) and obtains the load capacity of the externalpower supply device 1003 via the communication terminal.

As shown in FIG. 3A, in an embodiment, the energy control device 1003further includes a motor control switch 40. The motor control switch 40has a first terminal connected with the AC terminal a3 of thethree-level bidirectional DC-AC module 30 and a second terminalconnected with the motor M. When the current working mode of theelectric vehicle is a charge-discharge mode, the control module 60 isconnected with a third terminal of the motor control switch 40 and isconfigured to control the motor control switch 40 to turn off, and tocontrol the charge-discharge control module 50 to turn on so as to startthe three-level bidirectional DC-AC module 30, and thus charging thepower battery 10 by the external power supply device 1002.

In an embodiment of the present disclosure, as shown in FIG. 3A, thethree-level bidirectional DC-AC module 30 includes a first capacitor C1,a second capacitor C2, and a first IGBT1 to a twelfth IGBT12.

Specifically, the first capacitor C1 and the second capacitor C2 areconnected in series, the first capacitor C1 has a first terminalconnected with the first terminal of the power battery 10 and a secondterminal connected with a first terminal of the second capacitor C2, andthe second capacitor C2 has a second terminal connected with the secondterminal of the power battery 10, in which a first node J1 is definedbetween the first capacitor C1 and the second capacitor C2, in otherwords, the first capacitor C1 and the second capacitor C2 are connectedbetween the first DC terminal a1 and the second DC terminal a2 of thethree-level bidirectional DC-AC module 30. The first IGBT1 and a secondIGBT2 are connected in series and are connected between the first DCterminal a1 and the second DC terminal a2 of the three-levelbidirectional DC-AC module 30, in which a second node J2 is definedbetween the first IGBT1 and the second IGBT2. A third IGBT3 and a fourthIGBT4 are connected in series and are connected between the first nodeJ1 and the second node J2. A fifth IGBT5 and a sixth IGBT6 are connectedin series and are connected between the first DC terminal a1 and thesecond DC terminal a2 of the three-level bidirectional DC-AC module 30,in which a third node J3 is defined between the fifth IGBT5 and thesixth IGBT6. A seventh IGBT7 and an eighth IGBT8 are connected in seriesand are connected between the first node J1 and the third node J3. Aninth IGBT9 and a tenth IGBT10 are connected in series and are connectedbetween the first DC terminal a1 and the second DC terminal a2 of thethree-level bidirectional DC-AC module 30, in which a fourth node J4 isdefined between the ninth IGBT9 and the tenth IGBT10. An eleventh IGBT11and a twelfth IGBT12 are connected in series and are connected betweenthe first node J1 and the fourth node J4. The second node J2, the thirdnode J3 and the fourth node J4 are configured as the AC terminal a3 ofthe three-level bidirectional DC-AC module.

As shown in FIG. 3A, the energy control device 1003 includes the firstcommon-mode capacitor C11 and the second common-mode capacitor C12. Thefirst common-mode capacitor C11 and the second common-mode capacitor C12are connected in series and connected between the first terminal and thesecond terminal of the power battery 10, in which the node between thefirst common-mode capacitor C11 and the second common-mode capacitor C12is grounded.

Generally, a leakage current is large in an inverter and grid systemwithout transformer isolation. Compared with a conventional two-levelsystem, the energy control device 1003 according to embodiments of thepresent disclosure adopts the three-level bidirectional DC-AC module 30.By using a three-level control and connecting the first common-modecapacitor C11 and the second common-mode capacitor C12 between the firstterminal and the second terminal of the power battery 10, a common-modevoltage can be reduced by half in theory and the large leakage currentproblem generally existing in controllers can also solved. A leakagecurrent at an AC side can also be reduced, thus satisfying electricalsystem requirements of different countries.

In an embodiment of the present disclosure, as shown in FIG. 3A, theenergy control device 1003 further includes the filtering module 70, thefiltering control module 80, the EMI-filter module 90 and a prechargingcontrol module 1007.

The filtering module 70 is connected between the three-levelbidirectional DC-AC module 30 and the charge-discharge control module 50and is configured to eliminate a harmonic wave. As shown in FIG. 3A, thefiltering module 70 includes inductors LA, LB, LC connected in paralleland capacitors C4, C5, C6 connected in parallel, in which the inductorLA is connected with the capacitor C6 in series, the inductor LB isconnected with the capacitor C5 in series and the inductor LC isconnected with the capacitor C4 in series.

A shown in FIG. 3A, the filtering control module 80 is connected betweenthe first node J1 and the filtering module 70, and the control module 60controls the filtering control module 80 to turn off when the powersystem is in the driving mode. The filtering control module 80 may be acapacitor switching relay and may include a contactor K10. TheEMI-filter module 90 is connected between the charge-discharge socket 20and the charge-discharge control module 50 and is mainly configured tofilter interference of conduction and radiation.

The precharging control module 1007 is connected with thecharge-discharge control module 50 in parallel and is configured toprecharge the capacitors C4, C5, C6 in the filtering module 70, in whichthe precharging control module 1007 includes three resistors connectedin parallel and a three-phase contactor K9. When the vehicle is in thedischarging mode, the control module 60 controls the filtering controlmodule 80 to turn on and controls the precharging control module 1007 toprecharge the capacitors C4, C5, C6 in the filtering module 70 until avoltage of the capacitors C4, C5, C6 in the filtering module 70 reachesa predetermined threshold, and then the control module 60 controls theprecharging control module 1007 to turn off and controls thecharge-discharge control module 50 to turn on.

It should be noted that a position of the contactor K10 in FIG. 3A ismerely exemplary. In other embodiments of the present disclosure, thecontactor K10 may be disposed at other positions, provided that thefiltering module 70 can be turned off by using the contactor K10. Forexample, in another embodiment of the present disclosure, the contactorK10 can be connected between the three-level bidirectional DC-AC module30 and the filtering module 70.

In an embodiment of the present disclosure, as shown in FIG. 3A, thecharge-discharge control module 50 further includes a three-phase switchK8 and/or a single-phase switch K7 configured to implement a three-phaseor a single-phase charge-discharge.

With the charging system according to embodiments of the presentdisclosure, by employing the three-level bidirectional DC-AC module 30in the energy control device 1003 of the electric vehicle, a common-modevoltage is reduced, a leakage current is decreased and a harmonic waveis weakened. Furthermore, the DC-DC voltage increasing and decreasingmodule is not necessarily required in the energy control device 1003,thus realizing a high power charging, reducing a bus voltage, improvinga driving efficiency and shortening a charging time. In addition, thecharging pile is not necessarily required, thus the cost is reduced,which is beneficial to the popularization of the electric vehicle.

FIG. 3B is a flow chart of a method for controlling charging of anelectric vehicle according to an embodiment of the present disclosure.The method includes following steps.

At step 10, a modulated PWM signal is detected, which is transmittedbetween an energy control device and an external power supply device viaa charging connection device.

At step 20, a communication between the energy control device and theexternal power supply device is established according to the modulatedPWM signal.

At step 30, a three-level bidirectional DC-AC module and acharge-discharge control module of the energy control device arecontrolled to charge the power battery by the external power supplydevice.

In an embodiment, as shown in FIG. 3C, before the step 30, the methodfurther includes the following steps.

At step 301, it is determined whether there is a failure in the energycontrol device via a self-test.

At step 302, if no, the power battery is controlled to enter a chargingstate and provide a charging pathway.

In an embodiment, as shown in FIG. 3C, after the step 20, the methodfurther includes the following steps.

At step 201, a current carrying capacity of the charging connectiondevice and/or a load capacity of the external power supply device aredetected.

At step 202, step 30 is executed, if the current carrying capacity ofthe charging connection device and/or the load capacity of the externalpower supply device meet a predetermined requirement.

In other words, in an embodiment, the charge-discharge socket 20 and theexternal power supply device 1002 (such as, an external AC power supplyapparatus) are physically connected via the charging connection device1001 (such as, an AC charging gun). After the physical connection isfinished, the control module 60 and the external AC power supplyapparatus detect corresponding signals respectively to confirm whetherthe physical connection is successful. The control module 60 determineswhether a charging induction signal (i.e., a CC signal) is changedaccordingly. When the charging gun is disconnected with thecharge-discharge socket 20, the charging induction signal is a highlevel signal. If a sampled value of the charging induction signal isless than a first threshold and a duration of the charging inductionsignal with such value is larger than a second threshold, it isdetermined that the connection is successful, otherwise a promptindicating connection failure is pop-uped, and the charge-dischargesocket 20 and the external power supply device attempt re-connect witheach other. After the connection succeeds, the control module 60 beginsto communicate with the battery manager 103, that is, after it isconfirmed that the control module 60 has no failure free, the batterymanager 103 controls the power battery 10 to enter the charging stateand provide the charging pathway, otherwise, the battery manager 103does not allow the power battery 10 to be charged. Simultaneously, thecontrol module 60 communicates with the external AC power supplyapparatus to obtain a three-phase AC. After the communications betweenthe control module 60 and the battery manager 103 as well as between thecontrol module 60 and the external AC power supply apparatus arecompleted, a contactor K10 is turned on, such that the capacitors C4,C5, C6 are precharged, and the filtering module 70 may filter a gridvoltage. The control module 60 samples a three-phase current of the ACterminal of the three-level bidirectional DC-AC module and outputs a PWMsignal according to the SPWM algorithm to control the IGBT to turn on orturn off, thus stabilizing a voltage of a capacitor in the bus. Thecontrol module 60 samples a current of terminals of the power battery 10to control a charging power of the power battery 10. During the chargingprocess, if there is a failure or the power battery 10 is full, acharging finish control process flow is entered. During the chargingprocess, the control module 60 performs a real-time self-test andcommunicate with the battery manager 103 in real-time. If the controlmodule 60 has a failure or receives a message indicating that thecharging is finished or the charging is not allowed, the control module60 controls the energy control device 1003 to stop working and informsthe battery manager 103 via CAN information, and the battery manager 103is disconnected with a high voltage. The energy control device 1003controls the external AC power supply apparatus to disconnect with an ACinput by changing an amplitude of the CP signal.

With the method for controlling charging of an electric vehicleaccording to embodiments of the present disclosure, by controlling thethree-level bidirectional DC-AC module, the power battery is charged bythe external power supply device, such that the electric vehicle may becharged by a single-phase or a three-phase high power electricity, acharging efficiency of the electric vehicle is increased, a chargingtime is shortened, it is convenient for user to fast charge the electricvehicle anytime and anywhere.

As shown in FIG. 3D, in an embodiment, the power system may furtherinclude the high voltage distribution box 101, a dashboard 102, abattery manager 103 and a whole vehicle signal sampling apparatus 104.The control module 60 is connected with the high voltage distributionbox 101, the dashboard 102, the battery manager 103 and the wholevehicle signal sampling apparatus 104 respectively. The battery manager103 is connected with the high voltage distribution box 101 and thepower battery 10.

In an embodiment of the present disclosure, as shown in FIG. 4, thecontrol module 60 includes a control panel 201 and a driving panel 202.The control panel 201 includes two high-speed digital signal processingchips (i.e., DSP1 and DSP2). The two DSPs are connected and communicatewith a whole vehicle information interface 203. The two DSPs areconfigured to receive a bus voltage sampling signal, an IPM protectionsignal and an IGBT temperature sampling signal and so on sent from adriving unit on the driving panel 202, and to output a pulse widthmodulation (PWM) signal to the driving unit simultaneously.

Accordingly, the power system for the electric vehicle according toembodiments of the present disclosure has numerous functions includingmotor diving, vehicle control, AC charging, grid connection powersupplying, off-grid on-load and vehicle mutual-charging. Moreover, thepower system is established not by simply and physically combiningvarious functional modules, but by introducing peripheral devices basedon a motor driving control system, thus saving space and cost to amaximum extent and improving a power density.

Specifically, functions of the power system for the electric vehicle aresimply described below.

1. Motor Driving Function

A DC electricity from the power battery 10 is inverted into an ACelectricity by means of the three-level bidirectional DC-AC module 30,and the AC electricity is transmitted to the motor M. The motor M can becontrolled by a revolving transformer decoder technology and a spacevector pulse width modulation (SVPWM) control algorithm.

In other words, when the power system is powered to operate, as shown inFIG. 5, a process of determining a function of the power system includesthe following steps.

At step 501, the control module 60 is powered.

At step 502, it is determined whether the throttle is zero, and theelectric vehicle is in N gear, and the electric vehicle is braked by ahandbrake, and the charge connection signal (i.e. a CC signal) iseffective (i.e. the charge-discharge socket 20 is connected with thecharging connection device 1001, such as the charging gun), if yes, step503 is executed; if no, step 504 is executed.

At step 503, the power system enters a charge-discharge control process.

At step 504, the power system enters a vehicle control process.

After step 504, the control module 60 controls the motor control switch40 to turn on, the power system is in the driving mode, the controlmodule 60 samples the whole vehicle information and drives the motor Maccording to the whole vehicle information.

A motor driving control function is performed. As shown in FIG. 6, thecontrol module 60 sends a PWM signal to control the three-levelbidirectional DC-AC module 30, so as to invert the DC electricity fromthe power battery 10 into the AC electricity and transmit the ACelectricity to the motor M. Subsequently, the control module 60 obtainsa rotor location via a resolving transformer and samples the bus voltageand B-phase and C-phase currents of the motor so as to make the motor Moperate precisely. In other words, the control module 60 adjusts the PWMsignal according to the B-phase and C-phase current signals of the motorsampled by a current sensor and feedback information from the resolvingtransformer, such that the motor M may operate precisely.

Thus, by sampling the throttle, brake and gear information of the wholevehicle and determining a current operation state of the vehicle, anaccelerating function, a decelerating function and an energy feedbackfunction can be implemented, such that the whole vehicle can operatessafely and reliably under any condition, thus ensuring the safety,dynamic performance and comfort of the vehicle.

2. Charge-discharge Function

(1) Connection Confirmation and Start of Charge-discharge Function

As shown in FIG. 7, a process of determining whether to start thecharge-discharge function of the power system includes the followingsteps.

At step 701, the physical connection between the charging connectiondevice 1001 and the charge-discharge socket 20 is finished.

At step 702, a power supply apparatus determines whether the chargeconnection signal (i.e. the CC signal) is normal, if yes, step 703 isexecuted; if no, step 702 is returned for another determining.

At step 703, the power supply apparatus determines whether a voltage ofa CP detecting point is 9V. If yes, step 706 is executed; if no, step702 is returned for another determining. 9V is a predetermined value andis just exemplary.

At step 704, the control module 60 determines whether the chargeconnection signal (i.e. the CC signal) is normal. If yes, step 705 isexecuted; if no, step 704 is returned for another determining.

At step 705, the output charge connection signal and a charge indicatorlamp signal are pulled down.

At step 706, the power system performs the charge or discharge function,that is, the power system is in the charge-discharge mode.

As shown in FIG. 8, a process of controlling the power system in thecharging mode includes following steps.

At step 801, it is determined whether the power system starts to operatetotally after being powered. If yes, step 802 is executed; if no, step801 is returned for another determining.

At step 802, a resistance of a CC (charge connection) detecting point isdetected, so as to determine a capacity of the charging connectiondevice 1001.

At step 803, it is determined whether a PWM signal with a constant dutyratio at the CP detecting point is detected. If yes, step 804 isexecuted; if no, step 805 is executed.

At step 804, a message indicating the charge connection is normal andthe charge is prepared is sent out and a message indicating BMS permitsthe charge and a charge contactor turns on is received, and step 806 isexecuted.

At step 805, a failure occurs in the charge connection.

At step 806, the control module 60 turns on an internal switch.

At step 807, it is determined whether an AC external charging apparatusdoes not send a PWM wave in a predetermined time such as 1.5 seconds. Ifyes, step 808 is executed; if no, step 809 is executed.

At step 808, it is determined that the external charging apparatus is anexternal national standard charging post and the PWM wave is not sentout during the charge.

At step 809, the PWM wave is sent to the power supply apparatus.

At step 810, it is determined whether the AC input is normal in apredetermined time such as 3 seconds. If yes, step 813 is executed; ifno, step 811 is executed.

At step 811, a failure occurs in the AC external charging apparatus.

At step 812, the failure is processed.

At step 813, the power system enters the charging stage.

In other words, as shown in FIGS. 7 and 8, after the power supplyapparatus and the control module 60 detect themselves and no failureoccurs therein, the capacity of the charging connection device 1001 maybe determined by detecting a voltage of the CC signal, and it isdetermined whether the charging connection device 1001 is connectedtotally by detecting the CP signal. After it is determined that thecharging connection device 1001 is connected totally, the messageindicating the charge connection is normal and the charge is prepared issent out, and the three-phase switch K8 is controlled to turn on andthus the charge or discharge is prepared, i.e., functions such as the ACcharge function (G to V, grid to vehicle), the off-grid on-load function(V to L, vehicle to load), the grid connection function (V to G, vehicleto grid) and the vehicle-to-vehicle charging function (V to V, vehicleto vehicle), may be set via the dashboard.

(2) AC Charge Function (G to V)

When the power system receives a charging instruction from the dashboard102, the control module 60 sets a proper charging power according to apower supply capability of the charging pile and a capacity of acharging cable. Moreover, the control module 60 samples an informationof a grid, determines an electric system of the grid and selects controlparameters according to the electric system of the grid. After thecontrol parameters are selected, the control module 60 controls thecontactor K10 to turn on and then controls the three-phase switch K8 toturn on. At this time, the control module 60 controls the three-levelbidirectional DC-AC module 30 to rectify the AC electricity. A minimumcharging current is selected from a maximum charging current allowed bythe battery manager, a maximum current flow capacity allowed by thecharging pile and a maximum output power of the control module and usedas a predetermined target charging current and a closed-loop currentcontrol is performed on the power system, such that the in-vehicle powerbattery can be charged.

(3) Off-grid on-load Function (V to L)

When the power system receives a V to L instruction from the dashboard102, it is first determined whether a state of charge (SOC) of the powerbattery 10 is in an allowable discharging range. If yes, an outputelectric system is selected according to the V to L instruction. Amaximum output power is selected intelligently and control parametersare given according to the rated current of the charging connectiondevice 1001, and then the power system enters a control process. First,the control module 60 controls the three-phase switch K8 and thecontactor K10 to turn on and the three-level bidirectional DC-AC module30 inverts the DC electricity into the AC electricity, and thus electricapparatuses may be powered by the AC electricity directly via adedicated charge socket.

(4) Grid Connection Function (V to G)

When the power system receives a V to G instruction from the dashboard102, it is first determined whether the state of charge (SOC) of thepower battery 10 is in the allowable discharging range. If yes, anoutput electric system is selected according to the V to G instruction.A maximum output power is selected intelligently and controls parametersare given according to the rated current of the charging connectiondevice 1001, and the power system enters a control process. First, thecontrol module 60 controls the three-phase switch K8 and the contactorK10 to turn on and controls the three-phase bidirectional DC-AC module30 to invert the DC electricity into the AC electricity. And the controlmodule 60 performs the closed-loop current control on the power systemaccording to a predetermined target discharging current and the phasecurrents fed back from a current sampling, so as to implement the gridconnection discharging.

(5) Vehicle-to-vehicle Charging Function (V to V)

The V to V function requires a dedicated connection plug. When the powersystem determines that the charge connection signal (i.e. CC signal) iseffective and the connection plug is a dedicated charge plug for the Vto V function by detecting a level of the connection plug, the powersystem is prepared for an instruction from the dashboard. For example,assuming vehicle A charges vehicle B, the vehicle A is set in adischarging state, i.e. the vehicle A is set to perform the off-gridon-load function. The control module in vehicle A sends the messageindicating the charge connection is normal and the charge is prepared tothe battery manager 103. The battery manager 103 controls a charge ordischarge circuit to perform the pre-charging, and sends the messageindicating the charge is permitted and the charging contactor turns onto the control module after the pre-charging is finished. Then, thepower system performs the discharging function and sends the PWM signal.After the vehicle B receives the charging instruction, the power systemtherein detects a CP signal which determines that the vehicle A isprepared to supply power, and the control module 60 sends a normalconnection message to the battery manager. After receiving the message,the battery manager 103 finishes the pre-charging process and informsthe control module 60 that the whole power system is prepared for thecharge. Then, the vehicle-to-vehicle charging function (V to V) starts,and thus vehicles can charge each other.

In other words, after the power system is powered, when the V to Vinstruction from the dashboard 102 is received by the control module 60,the charge connection signal and relevant information on whole vehiclebattery management are detected, and the vehicle is set in an AC poweroutput state and sends the CP signal by simulating a charging box, so asto communicate with the vehicle to be charged. For example, a vehicle Ais set in the discharging mode and the control module 60 thereinsimulates the power supply apparatus to implement functions thereof, andthe vehicle B to be charged is connected with the vehicle A via adedicated charging wire, and thus the vehicle-to-vehicle chargingfunction is implemented.

In an embodiment, as shown in FIG. 9, a process of controlling the powersystem when the charging of the electric vehicle is finished includesthe following steps.

At step 1301, the power supply apparatus turns off a power supply switchto stop outputting the AC electricity, and step 1305 is executed.

At step 1302, the control module stops the charge and performs theunloading, and step 1303 is executed.

At step 1303, after the unloading is finished, the internal switch turnsoff and a charge finishing message is sent out.

At step 1304, a power outage request is sent out.

At step 1305, the charge is finished.

As shown in FIG. 10, a power supply apparatus 301 is connected with avehicle plug 303 of an electric vehicle 1000 via a power supply plug302, so as to charge the electric vehicle 1000. The power system of theelectric vehicle 1000 detects a CP signal via a detecting point 3 anddetects a CC signal via a detecting point 4, and the power supplyapparatus 301 detects the CP signal via a detecting point 1 and detectsthe CC signal via a detecting point 2. After the charge is finished, theinternal switches S2 in both the power supply plug 302 and the vehicleplug 303 are controlled to turn off.

In another embodiment, a plurality of power systems connected inparallel can be used in the electric vehicle to charge the powerbattery. For example, two power systems connected in parallel are usedto charge the power battery, and the two power systems use a commoncontrol module.

In the embodiment of the present disclosure, a charging system for theelectric vehicle includes the power battery 10, a first charging branch,a second charging branch and a control module 60.

The first charging branch includes a first rectifying unit (i.e., athree-level bidirectional DC-AC module 30) and a first charginginterface (i.e., a charge socket). The second charging branch includes asecond rectifying unit (i.e., a three-level bidirectional DC-AC module30) and a second charging interface (i.e., a charge socket). The powerbattery is connected with the first charging interface via the firstrectifying unit in turns and is connected with the second charginginterface via the second rectifying unit. The control module isconnected with the first rectifying unit and the second rectifying unitrespectively and is configured to control the grid to charge the powerbattery respectively via the first charging branch and the secondcharging branch, when receiving a charging signal.

In addition, as shown in FIG. 11, an embodiment of the presentdisclosure provides a method for controlling charging an electricvehicle. The method includes following steps.

At step S1101, when a control module determines that a first chargingbranch is connected with a power supply apparatus via a charge-dischargesocket and a second charging branch is connected with the power supplyapparatus via the charge-discharge socket, a control module sends acharge connection signal to a battery manager.

At step S1102, after receiving the charge connection signal sent fromthe control module, the battery manager detects and determines whether apower battery needs to be charged, if yes, a next step is executed.

At step S1103, the battery manager sends a charging signal to thecontrol module.

At step S1104, after receiving the charging signal, the control modulecontrols the grid to charge the power battery via the first chargingbranch and the second charging branch respectively.

With the charging system for the electric vehicle and the method forcontrolling charging the electric vehicle according to the aboveembodiments of the present disclosure, the control module controls thegrid to charge the power battery via the first charging branch and thesecond charging branch respectively, such that a charging power of theelectric vehicle is increased and a charging time is shortened greatly,thus implementing a fast charge and saving a time cost.

In some embodiments, the power system for the electric vehicle has awide compatibility and performs a single-phase/three-phase switchingfunction, and it can be adapted to various electric systems of differentcountries.

Specifically, as shown in FIG. 12, the charge-discharge socket 20 has afunction of switching between two charging sockets (such as a UnitedStates standard charging socket and a European standard chargingsocket). The charge-discharge socket 20 includes a single-phase chargingsocket 501 such as the United States standard charging socket, athree-phase charging socket 502 such as the European standard chargingsocket and two high-voltage connectors K503 and K504. A CC terminal, aCP terminal and a CE terminal are common terminals for the single-phasecharging socket 501 and the three-phase charging socket 502. Thesingle-phase charging socket 501 has an L-phase wire and an N-phase wireconnected with an A-phase wire and a B-phase wire of the three-phasecharging socket 502 via the connectors K503 and K504 respectively. Whenreceiving a single-phase charge or discharge instruction, the controlmodule 60 controls the connectors K503 and K504 to turn on, such thatthe A-phase and B-phase wires of the three-phase charging socket 502 areconnected with the L-phase and N-phase wires of the single-phasecharging socket 501 respectively. The three-phase charging socket 502does not operate, and instead of the L-phase and N-phase wires of thesingle-phase charging socket 501, the A-phase and B-phase wires of thethree-phase charging socket 502 are connected with the charge plug, andthus the control module 60 can perform the single-phase charge functionnormally.

Alternatively, as shown in FIG. 2, a standard 7-core socket is used andthe single-phase switch K7 is added between the N-phase and B-phasewires. When receiving the single-phase charge or discharge instruction,the control module 60 controls the single-phase switch K7 to turn on soas to connect the B-phase wire with the N-phase wire. Then, the A-phaseand B-phase wires are used as the L-phase and N-phase wiresrespectively, and the connection plug should be a dedicated connectionplug or a connection plug whose B-phase and C-phase wires are not used.

In other words, in some embodiments, the power system detects a voltageof the grid via the control module 60 and determines the frequency andthe single-phase/three-phase of the grid by calculation, so as to obtainthe grid electric system. Then, the control module 60 selects differentcontrol parameters according to a type of the charge-discharge socket 20and the grid electric system. Furthermore, the control module 60controls the three-level bidirectional DC-AC module 30 to rectify thealternating current controllably to obtain the DC electricity and totransmit the DC electricity to the power battery 10.

In another embodiment, as shown in FIG. 13, an off-grid on-loaddischarging socket includes two-core, three-core and four-core socketsconnected with a charge plug, and is configured to output single-phase,three-phase and four-phase electricity.

FIG. 14 is a block diagram of a power carrier communication system foran electric vehicle according to an embodiment of the presentdisclosure.

As shown in FIG. 14, the power carrier communication system 2000includes a plurality of control devices 110, a vehicle power cable 120and a plurality of power carrier communication devices 130.

Specifically, each of the control devices 110 has a communicationinterface, in which the communication interface may be, for example, butis not limited to, a serial communication interface SCI. The vehiclepower cable 120 supplies power to the control devices 110, and thecontrol devices 110 communicate with each other via the vehicle powercable 120. The power carrier communication devices 130 correspond to thecontrol devices 110 respectively, and the control devices 110 areconnected with corresponding power carrier communication devices 130 viatheir own communication interfaces respectively, and the power carriercommunication devices 130 are connected with each other via the vehiclepower cable 120. The power carrier communication devices 130 obtain acarrier signal from the vehicle power cable 120 so as to demodulate thecarrier signal and send the demodulated carrier signal to thecorresponding control device 110, and also receive and demodulateinformation sent from the corresponding control device 110 and send thedemodulated information to the vehicle power cable 120.

With reference to FIG. 14, the plurality of control devices 110 includea control device 1 to a control device N (N is larger than or equal to 2and is an integer). The plurality of power carrier communication devices130 corresponding to the plurality of control devices 110 include apower carrier communication device 1 to a power carrier communicationdevice N. For example, when the control device 1 needs to becommunicated with the control device 2, the control device 2 first sendsa carrier signal to the power carrier communication device 2, and thepower carrier communication device 2 demodulates the carrier signal andsends the demodulated carrier signal to the vehicle power cable 120.Then, the power carrier communication device 1 obtains the carriersignal from the vehicle power cable 120, and sends the demodulatedcarrier signal to the control device 1.

As shown in FIG. 15, each of the power carrier communication devices 130includes a coupler 131, a filter 133, an amplifier 134 and a modem 132connected sequentially.

Further, as shown in FIG. 16, the plurality of power carriercommunication devices 130, such as eight power carrier communicationdevices 1-8, are connected with a gateway 300 via a vehicle power cablebundle 121 and a vehicle power cable bundle 122, and each power carriercommunication device corresponds to one control device. For example, thepower carrier communication device 1 corresponds to a transmissioncontrol device 111, the power carrier communication device 2 correspondsto a generator control device 112, the power carrier communicationdevice 3 corresponds to an active suspension device 113, the powercarrier communication device 4 corresponds to an air-conditioner controldevice 114, the power carrier communication device 5 corresponds to anair bag 115, the power carrier communication device 6 corresponds to adashboard display 116, the power carrier communication device 7corresponds to a failure diagnosis device 117, and the power carriercommunication device 8 corresponds to an illumination device 118.

In this embodiment, as shown in FIG. 17, a method for receiving data bya power carrier communication system includes following steps.

At step 2101, the system is powered to start and a system program entersa state in which data is received from a vehicle power cable.

At step 2102, it is determined whether there is a carrier signal andwhether the carrier signal is correct, if yes, step 2103 is executed; ifno, step 2104 is executed.

At step 2103, the system starts to receive the data sent from thevehicle power cable, and step 2105 is executed.

At step 2104, the serial communication interface (SCI) is detected andit is determined whether there is data in the serial communicationinterface (SCI), if yes, step 2105 is executed; if no, step 2101 isreturned.

At step 2105, the system enters a state in which the data is received.

With the power carrier communication system for the electric vehicleaccording to embodiments of the present disclosure, a data transmissionand sharing among various control systems in the electric vehicle can beachieved without increasing internal cable bundles of the vehicle.Moreover, a power carrier communication using the power cable as acommunication medium avoids constructing and investing a newcommunication network, thus reducing the manufacturing cost andmaintenance difficulty.

FIG. 18 is a schematic diagram of a connection between a motorcontroller for an electric vehicle and other parts of the electricvehicle according to an embodiment of the present disclosure. The motorcontroller is connected with a power battery via a DC interface, andconnected with a grid via an AC interface so as to charge the powerbattery, and connected with a load or other vehicles via an AC interfaceso as to discharge the load or the other vehicles. In the embodiment ofthe present disclosure, the motor controller for the electric vehicleincludes: a three-level bidirectional DC-AC module, a motor controlswitch, a charge-discharge control module and a control module.

The three-level bidirectional DC-AC module has a first DC terminalconnected with a first terminal of the power battery and a second DCterminal connected with a second terminal of the power battery. Themotor control switch has a first terminal connected with an AC terminalof the three-level bidirectional DC-AC module and a second terminalconnected with the motor. The charge-discharge control module has afirst terminal connected with the AC terminal of the three-levelbidirectional DC-AC module and a second terminal connected with thecharge-discharge socket. The control module is connected with the motorcontrol switch and the charge-discharge control module respectively andis configured to control the motor control switch and thecharge-discharge control module according to a current working mode of apower system.

The motor controller according to embodiments of the present disclosurehas a bidirectional property, i.e. the motor controller not only mayimplement the charging of the electric vehicle by an external grid, forexample, the direct charging of the electric vehicle with an ACelectricity, but also may implement the discharging of the electricvehicle to an external apparatus. Therefore, the motor control hasvarious functions, thus facilitating the use of a user largely. Inaddition, with the three-level control, the common-mode voltage isgreatly reduced, the leakage current is decreased, the harmonic wave isweakened, and the charging efficiency is improved. Moreover, a charginggenerator is not required in the system by using the AC electricity todirectly charge the electric vehicle, thus saving a cost of a chargingstation. In addition, the electric vehicle can be charged by using alocal AC electricity anytime and anywhere.

In an embodiment of the present disclosure, when the power system is inthe driving mode, the control module controls the motor control switchto turn on and controls the charge-discharge control module to turn off.When the power system is in the charge-discharge mode, the controlmodule controls the motor control switch to turn off and controls thecharge-discharge control module to turn off so as to start thethree-level bidirectional DC-AC module.

In an embodiment, the power system for the electric vehicle furtherincludes a first common-mode capacitor and a second common-modecapacitor. The first common-mode capacitor and the second common-modecapacitor are connected in series and connected between the firstterminal and the second terminal of the power battery, in which a nodebetween the first common-mode capacitor and the second common-modecapacitor is grounded.

In an embodiment, the power system for the electric vehicle includes afiltering module. The filtering module is connected between the ACterminal of the three-level bidirectional DC-AC module and thecharge-discharge control module.

In an embodiment, the power system for the electric vehicle includes afiltering control module. The filtering control module is connectedbetween the first node and the filtering module, and the control modulecontrols the filtering control module to turn off when the vehicle is ina driving mode.

In an embodiment, the power system for the electric vehicle includes anEMI-filter module. And the EMI-filter module is connected between thecharge-discharge socket and the charge-discharge control module and isconfigured to filter interference of conduction and radiation.

In an embodiment, the charge-discharge control module further includes:a three-phase switch and/or a single-phase switch configured toimplement a three-phase or a single-phase charge-discharge.

In an embodiment, the motor controller is connected with the powerbattery and is also connected with loads, the grid and other electricvehicles.

Any procedure or method described in the flow charts or described in anyother way herein may be understood to include one or more modules,portions or parts for storing executable codes that realize particularlogic functions or procedures. Moreover, advantageous embodiments of thepresent disclosure includes other implementations in which the order ofexecution is different from that which is depicted or discussed,including executing functions in a substantially simultaneous manner orin an opposite order according to the related functions. This should beunderstood by those skilled in the art which embodiments of the presentdisclosure belong to.

The logic and/or step described in other manners herein or shown in theflow chart, for example, a particular sequence table of executableinstructions for realizing the logical function, may be specificallyachieved in any computer readable medium to be used by the instructionexecution system, device or equipment (such as the system based oncomputers, the system including processors or other systems capable ofobtaining the instruction from the instruction execution system, deviceand equipment and executing the instruction), or to be used incombination with the instruction execution system, device and equipment.

It is understood that each part of the present disclosure may berealized by the hardware, software, firmware or their combination. Inthe above embodiments, a plurality of steps or methods may be realizedby the software or firmware stored in the memory and executed by theappropriate instruction execution system. For example, if it is realizedby the hardware, likewise in another embodiment, the steps or methodsmay be realized by one or a combination of the following techniquesknown in the art: a discrete logic circuit having a logic gate circuitfor realizing a logic function of a data signal, an application-specificintegrated circuit having an appropriate combination logic gate circuit,a programmable gate array (PGA), a field programmable gate array (FPGA),etc.

Those skilled in the art shall understand that all or parts of the stepsin the above exemplifying method of the present disclosure may beachieved by commanding the related hardware with programs. The programsmay be stored in a computer readable storage medium, and the programsinclude one or a combination of the steps in the method embodiments ofthe present disclosure when run on a computer.

In addition, each function cell of the embodiments of the presentdisclosure may be integrated in a processing module, or these cells maybe separate physical existence, or two or more cells are integrated in aprocessing module. The integrated module may be realized in a form ofhardware or in a form of software function modules. When the integratedmodule is realized in a form of software function module and is sold orused as a standalone product, the integrated module may be stored in acomputer readable storage medium.

The storage medium mentioned above may be read-only memories, magneticdisks or CD, etc.

Reference throughout this specification to “an embodiment,” “someembodiments,” “one embodiment”, “another example,” “an example,” “aspecific example,” or “some examples,” means that a particular feature,structure, material, or characteristic described in connection with theembodiment or example is included in at least one embodiment or exampleof the present disclosure. Thus, the appearances of the phrases such as“in some embodiments,” “in one embodiment”, “in an embodiment”, “inanother example,” “in an example,” “in a specific example,” or “in someexamples,” in various places throughout this specification are notnecessarily referring to the same embodiment or example of the presentdisclosure. Furthermore, the particular features, structures, materials,or characteristics may be combined in any suitable manner in one or moreembodiments or examples.

Although explanatory embodiments have been shown and described, it wouldbe appreciated by those skilled in the art that the above embodimentscannot be construed to limit the present disclosure, and changes,alternatives, and modifications can be made in the embodiments withoutdeparting from spirit, principles and scope of the present disclosure.

What is claimed is:
 1. A charging system for an electric vehicle,comprising: a charge-discharge socket configured for connecting with anexternal power supply device through a charging connection devicecomprising a first plug configured to connect with the external powersupply device and a second plug configured to connect with thecharge-discharge socket; and an energy control device configured toconnect with a power battery, comprising: a three-level bidirectionalDC-AC module having a first DC terminal configured to connect with afirst terminal of the power battery and a second DC terminal configuredto connect with a second terminal of the power battery; acharge-discharge control module having a first terminal connected withan AC terminal of the three-level bidirectional DC-AC module and asecond terminal connected with the charge-discharge socket; a filteringmodule having a first terminal connected to the AC terminal of thethree-level bidirectional DC-AC module and a second terminal connectedto the charge-discharge control module; and a control module connectedwith a third terminal of the charge-discharge control module and acontrol terminal of the three-level bidirectional DC-AC module andconfigured to control the charge-discharge control module according to acurrent working mode of the electric vehicle; wherein the energy controldevice is configured to communicate with the external power supplydevice communicate by transmitting a modulated PWM signal via thecharging connection device, and the control module is configured tocontrol the three-level bidirectional DC-AC module and thecharge-discharge control module to charge the power battery by theexternal power supply device; and the three-level bidirectional DC-ACmodule comprises: a first capacitor and a second capacitor connected inseries and connected between the first DC terminal and the second DCterminal of the three-level bidirectional DC-AC module, a first node isdefined between the first capacitor and the second capacitor; a firstIGBT and a second IGBT connected in series and connected between thefirst DC terminal and the second DC terminal of the three-levelbidirectional DC-AC module, a second node is defined between the firstIGBT and the second IGBT; a third IGBT and a fourth IGBT connected inseries and connected between a third terminal of the filtering moduleand the second node; a fifth IGBT and a sixth IGBT connected in seriesand connected between the first DC terminal and the second DC terminalof the three-level bidirectional DC-AC module, a third node is definedbetween the fifth IGBT and the sixth IGBT; a seventh IGBT and an eighthIGBT connected in series and connected between the third terminal of thefiltering module and the third node; a ninth IGBT and a tenth IGBTconnected in series and connected between the first DC terminal and thesecond DC terminal of the three-level bidirectional DC-AC module, afourth node is defined between the ninth IGBT and the tenth IGBT; aneleventh IGBT and a twelfth IGBT connected in series and connectedbetween the third terminal of the filtering module and the fourth node;and the second node, the third node and the fourth node are configuredas the AC terminal of the three-level bidirectional DC-AC module.
 2. Thecharging system according to claim 1, further comprising: a batterymanager communicated with the control module via CAN and configured tocontrol the power battery to provide a charging pathway when the controlmodule is failure free via a self-test.
 3. The charging system accordingto claim 1, wherein the control module is further configured to detect acurrent carrying capacity of the charging connection device and/or aload capacity of the external power supply device.
 4. The chargingsystem according to claim 1, wherein the charging connection devicecomprises: a plurality of high-voltage terminals, a first detectionterminal, a second detection terminal and a communication terminal;wherein the external power supply device and the energy control devicedetermine a connection state of the first plug and the second plugaccording to the first detection terminal and the second detectionterminal, and the external power supply device and the energy controldevice communicate with each other via the communication terminal. 5.The charging system according to claim 4, wherein the energy controldevice detects the current carrying capacity of the charging connectiondevice via the second detection terminal and obtains the load capacityof the external power supply device via the communication terminal. 6.The charging system according to claim 1, wherein the energy controldevice further comprises a motor control switch having a first terminalconnected with the AC terminal of the three-level bidirectional DC-ACmodule and a second terminal configured to connect with a motor for theelectric vehicle, wherein the control module is connected with a thirdterminal of the motor control switch and is configured to control themotor control switch to turn off, and to control the charge-dischargecontrol module to turn on so as to start the three-level bidirectionalDC-AC module, when the current working mode of the electric vehicle is acharge-discharge mode.
 7. The charging system according to claim 1,wherein the energy control device further comprises: a first common-modecapacitor and a second common-mode capacitor connected in series andconnected between the first terminal and the second terminal of thepower battery, in which a node between the first common-mode capacitorand the second common-mode capacitor is grounded.
 8. The charging systemaccording to claim 1, wherein the energy control device furthercomprises: a filtering control module connected between the first nodeand the third terminal of the filtering module, in which the controlmodule controls the filtering control module to turn off when thecurrent working mode of the electric vehicle is a driving mode.
 9. Thecharging system according to claim 1, wherein the energy control devicefurther comprises: an EMI-filter module connected between thecharge-discharge socket and the charge-discharge control module.
 10. Thecharging system according to claim 1, wherein the energy control devicefurther comprises: a precharging control module connected with thecharge-discharge control module in parallel and configured to prechargea capacitor in the filtering module, wherein when the current workingmode of the first electric vehicle is the discharging mode, the controlmodule controls the filtering control module to turn on and controls theprecharging control module to precharge the capacitor in the filteringmodule until a voltage of the capacitor in the filtering module reachesa predetermined threshold, and then the control module controls theprecharging control module to turn off and controls the charge-dischargecontrol module to turn on.
 11. The charging system according to claim 1,wherein the charge-discharge control module further comprises: at leastone of a three-phase switch and a single-phase switch configured toimplement a three-phase charge-discharge or a single-phasecharge-discharge.
 12. A method for controlling charging of an electricvehicle, comprising: detecting a modulated PWM signal transmittedbetween an energy control device and an external power supply device viaa charging connection device; establishing a communication between theenergy control device and the external power supply device according tothe modulated PWM signal; and controlling a three-level bidirectionalDC-AC module and a charge-discharge control module of the energy controldevice to charge a power battery by the external power supply device,wherein the three-level bidirectional DC-AC module comprises: a firstcapacitor and a second capacitor connected in series and connectedbetween a first DC terminal and a second DC terminal of the three-levelbidirectional DC-AC module, a first node is defined between the firstcapacitor and the second capacitor; a first IGBT and a second IGBTconnected in series and connected between the first DC terminal and thesecond DC terminal of the three-level bidirectional DC-AC module, asecond node is defined between the first IGBT and the second IGBT; athird IGBT and a fourth IGBT connected in series and connected between afiltering module and the second node; a fifth IGBT and a sixth IGBTconnected in series and connected between the first DC terminal and thesecond DC terminal of the three-level bidirectional DC-AC module, athird node is defined between the fifth IGBT and the sixth IGBT; aseventh IGBT and an eighth IGBT connected in series and connectedbetween the filtering module and the third node; a ninth IGBT and atenth IGBT connected in series and connected between the first DCterminal and the second DC terminal of the three-level bidirectionalDC-AC module, a fourth node is defined between the ninth IGBT and thetenth IGBT; an eleventh IGBT and a twelfth IGBT connected in series andconnected between the filtering module and the fourth node; and thesecond node, the third node and the fourth node are configured as the ACterminal of the three-level bidirectional DC-AC module.
 13. The methodaccording to claim 12, further comprising: determining whether there isa failure in the energy control device via a self-test; if no,controlling the power battery to provide a charging pathway.
 14. Themethod according to claim 13, further comprising: detecting a currentcarrying capacity of the charging connection device and/or a loadcapacity of the external power supply device; controlling thethree-level bidirectional DC-AC module and the charge-discharge controlmodule of the energy control device to charge the power battery by theexternal power supply device, when the current carrying capacity of thecharging connection device and/or the load capacity of the externalpower supply device meet a predetermined requirement.